TECHNOLOGY × HUMAN EVOLUTION

The First Vaccine

1796 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

Giving someone a mild disease caught from cattle, on purpose, to protect them from a deadly one caught from people. It worked a century before anyone knew what a virus was, and the reason it worked, that the two diseases are close enough for the immune system to confuse them, would not be understood for longer still.

Why it matters

Inoculating with smallpox itself was old, and killed a share of those who took it. Using a milder relative made protection survivable, and therefore repeatable, and therefore something a whole population could be given. That is what turned a treatment into a campaign, and the campaign ended in the only deliberate extinction our species has ever carried out.

Dating & uncertainty

Inoculation with smallpox itself was practised in Asia and Africa long before. What 1796 adds is the use of a milder related disease, cowpox, which made the protection survivable and repeatable.

Sources

1. Riedel (2005), Proceedings (Baylor University Medical Center) · Edward Jenner and the history of smallpox and vaccination
2. Ahamed & colleagues (2024), Cureus · Jenner's legacy: how Edward Jenner's smallpox vaccine changed public health
3. Foege (1998), Bulletin of the World Health Organization · Smallpox eradication in west and central Africa revisited

Earth history as one day

23:59:59.99564.4 ms before midnight

if Earth’s 4.54 billion years were compressed into a single day